This invention relates generally to wireless communication systems and, more particularly, to manufacturing radio frequency identification (RFID) components.
At least some known RFID systems include a transponder, an antenna, and a transceiver with a decoder, or a reader. The transponder typically includes a radio frequency integrated circuit, and an antenna positioned on a substrate, such as an inlet or tag. The antenna receives RF energy from the reader wirelessly and transmits the data encoded in the received RF energy to the radio frequency integrated circuit.
RF transponder “readers” utilize an antenna as well as a transceiver and decoder. When a transponder passes through an electromagnetic zone of a reader, the transponder is activated by the signal from the antenna. The reader decodes the data on the transponder and this decoded information is forwarded to a host computer for processing. Readers or interrogators can be fixed, mobile or handheld devices, depending on the particular application.
Several different types of transponders are utilized in RFID systems, including passive, semi-passive, and active transponders. Each type of transponder may be read only or read/write capable. Passive transponders obtain operating power from the radio frequency signal of the reader that interrogates the transponder. Semi-passive and active transponders are powered by a battery, which generally results in a greater read range. At least some known semi-passive transponders operate on a timer and periodically transmit information to the reader. Transponders are also activated when they are read or interrogated by a reader. Active transponders are capable of initiating communication with a reader, whereas passive and semi-passive transponders are activated only when they are read by another device first. When multiple transponders are located in a radio frequency field, each transponder may be read individually or multiple transponders may be read substantially simultaneously. Additionally, in various embodiments, one or more environmental sensors are coupled to the transponders to sense environmental conditions, such as temperature, pressure, humidity, vibration, and shock. The status of the environmental condition is then communicated to the reader.
RFID transponders for articles in a global supply chain are mass produced in rolls of many hundreds or thousands of tags. Verifying the proper operation of such a large quantity of tags is laborious and time consuming. Verification of operation after the tag is fully assembled with an antenna, for example, in a completed strap, wastes the material of the strap and antenna and the manufacturing steps required to complete the strap if the transponder is found to be defective during testing of the completed strap. Accordingly, is it not desirable to attach an antenna and complete assembly of the transponder if it is defective. However, testing a large quantity of transponders before the strap is completed is difficult because communicating with the transponder uses the antenna.